Organizations are looking for ways to get more out of their already strained IT infrastructure as they face new technological and economic pressures. They are also trying to satisfy a broad set of users (internal and external to the enterprise) who demand improvements in their quality of service (QoS), regardless of increases in the number of users and applications. Cloud computing offers attractive opportunities to reduce costs, accelerate development, and increase the flexibility of the IT infrastructure, applications, and services. Infrastructure as a service (IaaS) is the typical starting point for most organizations when moving to a cloud computing environment. IaaS can be used for the delivery of resources such as compute, storage, and network services through a self-service portal. With IaaS, IT services are delivered as a subscription service, eliminating up-front costs and driving down ongoing support costs. IBM® has defined the Cloud Computing Reference Architecture (CCRA) based on years of experience of working with customers who have implemented cloud-computing solutions. The IBM CCRA is a blueprint or guide for architecting cloud-computing implementations. This IBM RedguideTM publication highlights the Cloud Enabled Data Center adoption pattern and describes how you can use it to define an IaaS solution. This guide is intended for chief technology officers, data center architects, IT architects, and application architects who want to understand the cloud-computing infrastructure necessary to support their applications and services by using an IaaS solution. It explains the technical and business benefits of a Cloud Enabled Data Center solution. It introduces a Cloud Enabled Data Center maturity model where each maturity level corresponds to an increase in the degree of automation and the cloud-computing capabilities that are available. In addition, this guide describes the architectural framework provided by the IBM CCRA and expla